Compute Orbital Gradient

Hi all,
I want to compute the gradient vector of HOMO and LUMO energies with respect to atomic cartesian coordinates (analytically if possible). I’ve found in the documentation that the “psi4.core.HF” class has a method called “compute_orbital_gradient”, but not detailed information is available, also I couldn’t found this method when inspecting the class in Python.
Is there a way for doing this?

Thanks.

compute_orbital_gradient computes the gradient of the SCF energy with respect to changes in the orbitals for Hartree-Fock computations. It will be available Python side in 1.3, but this is not what you’re looking for.

Do you know if analytic expressions for orbital energies have been reported? I’ve never even heard of them, but it sounds plausible.

Thanks for your answer!
I haven’t seen them really…, but I’m trying to find an expression.
For now I will just do an approximation by the N+1 and N-1 electron system.